I for one full well remembered that it's entirely optional, it's just that people are crying "unbalanced" when it is entirely balanced.
I voted in the poll that I want to see it as an offshoot of the standard metagame, ie Standard w/ Miracle Shooter.
The possibilities of the metagame are near infinite, and with Miracle Shooter, the possibilities extend even farther. There's gonna be stall, of course, there's also gonna be stall breakers. There's gonna be teams that are gonna try to use items effectively, teams that are there to counter and use the items effectively themselves. There won't be a shortage of Scarf Ditto, for sure.
I think the majority of strategy will be based around using the Full Revive instead of the X-Attack. Let's face it, wasting a turn to boost +6 is pretty risky, while on the other hand, there isn't much risk involved into reviving your early-game sweeper.
I eagerly await this as an an option to add during simulator battles, and I plan to create a team that can use the items effectively.
It's just like Double Battles, Triple Battles, Rotation Battles, and Little Cup. It's not Standard Metagame, it's an optional offshoot. Nobody is forcing you to use items, and I don't expect samefags to be playing around with it much anyways.